The goals of the Neuropathology Core (NPC) will be to provide standardize neuropathologic assessment of brains obtained at autopsy from study patients who have been followed clinically, using neuropsychological evaluations and neuroimaging, in order to characterize the relative contributions of ischemic vascular lesions and parenchymal degenerative changes (e.g. of Alzheimer disease) to a given patient's dementia. Comparisons of specific neuropathologic parameters (see below) will be made among ischemic vascular dementia (IVD), Alzheimer and control patients. We will operationalize assessment of neuropathologic substrates of IVD by evaluating both (a) extent, and (b) distribution of encephalomalacic lesions that may contribute to dementia. A neuropathologic data base will be maintained and data will be provided to other projects as necessary to facilitate correlations between pre- mortem (including metabolic) imaging studies and postmortem brain findings, with an emphasis on defining radiographic features on lacunar infarcts, and their possible impact upon cortical integrity by mechanisms of retrograde and trans-synaptic degeneration. Possible neuroanatomical correlates of ischemic vascular dementia )IVD) to be evaluated in detail will include changes within white matter (axons, myelin sheaths) and densities and sizes of neurons projecting into the white matter (in conjugation with Project #3). Possible neuropathologic substrates of IVD to be evaluated, using immunohistochemistry and quantitative morphometry, will include (a) microvascular lesions characterized as abnormal distributions/densities of glucose transporter-immunoreactive capillaries, and hypertrophic arterioles, (b) secondary injurious effects of microvasculopathy upon adjacent brain parenchyma (e.g. axon/myeline densities of glucose transporter-immunoreactive capillaries, and hypertrophic arterioles, (b) secondary injurious effects of microvasculopathy upon adjacent brain parenchyma (e.g. axon/myelin densities , APP expression) and inflammatory/reactive cells (microglia, astrocytes), and (c) hippocampal abnormalities indicative of hippocampal sclerosis or scarring. Neuropathologic data will be provided to the investigational projects and all clinical/experimental data will be re- evaluated in these projects in light of neuropathologic outcomes. The intended result is to provide the most detailed available pathophysiologic representation of IVD based upon multi-modality functional and neuroanatomical patient evaluation.